McGill University Thèses et mémoires par auteur commençant par O

The Panama Canal Watershed (PCW) provides water to operate the Canal, generate hydroelectricity, and supply water provisions to the local and metropolitan populations. With a maxed-out water budget, however, this region has little room to accommodate the possible effects of unsustainable land-use changes or of climate change, both of which threaten to alter water flows and timings. On the other hand, the water storage capacity of the canal reservoirs, necessary for water use during the dry season deficit, is compromised by sedimentation – the result of erosion and landslides on mismanaged lands. Given this context, tools must be developed to …  Read more

Turcotte, Rene (Supervisor)  Read more

Gelatin was extracted from shark and salmon skins by an enzyme aided process. A three factor, two level central composite rotatable design was used to optimize the process. The factors were namely, enzyme: dry fish skin weight ratio, incubation time, and temperature. The data were analyzed by response surface methodology to determine the optimum conditions for the deproteinization, demineralization and extraction process variables. Optimum conditions for deproteinization of shark skin by trypsin was about 25°C for 3h, and an E/S ratio of 0.08% (w/w). That for salmon was optimum at 25°C for 1 h with an E/S ratio of 1:1000. …  Read more

For over 80 years, social psychology has studied intergroup prejudice as a phenomenon situated within the psyche of the individual. Yet people live in societies, which surely play some role in shaping the attitudes of individuals in those societies. The burgeoning area of regional prejudice – the study of prejudice incorporating elements of individuals situated within geographical regions – refocuses attention on the socio-geopolitical influences on prejudice and its associated outcomes. The exact nature of the relationship between individual-level prejudice and regional prejudice remains unclear. In fact, because of limited research attention, there are basic questions and information about regional …  Read more

The current research tested whether the passing of government legislation, signaling the prevailing attitudes of the local majority, was associated with changes in citizens’ attitudes. Specifically, with ~1 million responses over a 11-year window, we test whether state-by-state same-sex marriage legislation was associated with decreases in anti-gay implicit and explicit bias. Results across five operationalizations consistently provide support for this possibility. Both implicit and explicit bias were decreasing prior to same-sex marriage legalization, but decreased at a sharper rate following legalization. Moderating this effect was whether states passed legislation locally. While states passing state-level legislation experienced a greater decrease in …  Read more

Les modèles d'ordre réduit sont recherchés afin de minimiser le nombre total de variables nécessaires à la résolution d'une solution d'ordre complet. Par conséquent, le coût de calcul nécessaire à l'obtention d'une solution approximative est théoriquement réduit. Un type de modèle d'ordre réduit est le modèle basé sur la projection. Des méthodes basées sur la projection ont été utilisées pour générer des modèles d'ordre réduit conservateurs et potentiellement stables. Deux approches, Galerkin et Petrov-Galerkin, sont utilisées en raison de leur simplicité. Bien que la stabilité de ces approches ne soit généralement pas garantie, elles peuvent être modifiées pour prouver la …  Read more

An attempt is made to determine whether the interaction of pack ice and ocean waves can be studied usefully in a laboratory model. Ocean waves and ice floes are simulated by waves in a laboratory channel and by thin floating sheets of polyethylene. [...]  Read more

Hinsberg, Vincent Johan van (Supervisor2)  Read more

L'étude actuelle traite de la pénurie des enseignants au Japon dûe à un taux croissant d’attrition. Une revue approfondie de la littérature indique que les enseignants quittent leur profession en raison de plusieurs facteurs. La première raison est une charge de travail intense qui les épuise physiquement et mentalement. Des niveaux élevés de stress liés au travail vécus par les enseignants sont régulièrement associés à des résultats négatifs, notamment une diminution de la qualité de l'enseignement, une altération du bien-être et de la santé des enseignants, et finalement, l'épuisement professionnel. Par conséquent, cette étude explore l'épuisement professionnel des enseignants comme …  Read more

This study explores the impact of racism on the identity construction of Black Nigerian youth in Montreal. Several themes, related to socialization, family, education, integration, employment, racism, marginalization and social exclusion emerged from phenomenological interviews of 10 Nigerian youth, 5 parents and 3 community leaders. These expressions of their lived experiences exposed the negative impact of racism and racist discourses of the Canadian society on minority groups. It simultaneously showed, through the acquisition of pro-social skills, the extent that marginalized groups, as depicted by Nigerian youth, formulate resiliency and strategies to resist and deconstruct their "othering," in order to construct …  Read more

The primary cell wall of dicotyledonous plants consists largely of cellulose and hemicelluloses embedded in a gel of pectins. Pectins are a heterogeneous group of polysaccharides that are synthesized in the Golgi apparatus and transported to the cell surface via secretory vesicles. Antibody studies have shown that there is a non-uniform and dynamic occurrence of different pectins across cell and tissue types, demonstrating the complexity of cell wall structure. How pectins are targeted to distinct cell wall domains, however, is unclear. To investigate the establishment of plasma membrane domains involved in pectin targeting, Arabidopsis thaliana mucilage secretory cells (MSCs) were …  Read more

RésuméINTRODUCTION: La transplantation de moelle osseuse ou même la formation de moelle extramédullaire est souvent connue pour entraîner une nouvelle formation osseuse. La moelle extramédullaire peut se former à la suite de maladies hématologiques. Cependant, il a également été rapporté qu'elle peut survenir après une blessure telle qu'une chirurgie ou un autre traumatisme. L'implantation de biomatériaux entraîne souvent une inflammation stérile et du tissu hématopoïétique extramédullaire est occasionnellement signalé comme une découverte fortuite. Le système le plus simple rapporté pour induire pré-cliniquement de la moelle extramédullaire et de l'os ectopique était un tube en verre à extrémité ouverte. Cette étude …  Read more

This thesis discusses 3D seismic exploration for hydrothermal dolomite (HTD) reservoirs. During this project, I utilized some of the existing algorithms as well as developed my own methods. I mentioned that HTD reservoirs constitute an important hydrocarbon play-type the world over, and are particularly important within the Ordovician aged Trenton-Black River Group in eastern North America. I noted that 3D seismic is the best tool to explore for HTD but it is adversely affected by random noise and acquisition footprint which must be attenuated. I designed a post-stack processing flow that can be applied to attenuate noise, highlight fault terminations, …  Read more

This thesis is essentially a report on the work done on War Research projects during the past year. It consists of two parts: A. The Combustion of Hydrocarbons and Pollution of the Atmosphere to Render Automotive Equipment Inactive. B. The Synthesis of Divinyl Sulfide from Acetylene. Work was started during the fall of 1939 on the Oxidation of Hydrocarbon - Alcohol mixtures, but was early discontinued in favor of a war research project, the Synthesis of Divinyl Sulfide. This problem developed into a long time project and was temporarily abandoned in favor of the problem on the Combustion of Hydrocarbons …  Read more

Various compounds were investigated to determine their pro knock activity by adding them to the air intake of, or to the gasoline used by and Ethyl 30 B Knock Testing Engine. The best compound tested was arsenic tri chloride which requires 5.8 parts per million of air by volume to cause a decrease of ten octane units in a leaded gasoline. It was found that the best knock inducer elements were in order of effectiveness: arsenic, antimony and phosphorous. Mercury, vanadium and chromium were also found to be effective. Among the radicals the halogens were most effective, the order being …  Read more

Two recent electronic albums, OIL OF EVERY PEARL’S UN-INSIDES by SOPHIE and PROTO by Holly Herndon, use sound in ways that extend the provenance of the voice, and in turn the capacities of the physical body. For SOPHIE, this is accomplished through her inventive use of synthesis and vocal processing, through which organic sounds are mimicked and reproduced with a palpably technologized difference. In contrast, Holly Herndon has developed an artificial intelligence machine which can imitate her voice, and which is learning the logic of her choral compositions, and performances. Both artist’s works challenge conceptions of ‘authentic’ electronic music, SOPHIE …  Read more

The development of modern business gradually has resulted in the substitution of method in operations in place of haphazard chance, and has rewarded richly those corporations and small businesses which have followed some well coordinated scheme to reach their objectives. The value of planning is admitted generally, but the scope of its possible employment and the details of its operation seldom are recognized. Proper planning of all operations is regarded as an excellent theory by the average individual in business, but he is either ignorant of the fact or not willing to reoognize that planning can be applied to his …  Read more

It has been most unfortunate that nearly all the research that has been done on cold injury has been under the driving urgency to find a method of treatment or prevention, and the fundamental work that might have contributed to our understanding of the nature of cold injury has been lacking because there was not time for it.  Read more

Philippe Archambault (Supervisor2)  Read more

Ptito, Alain (Supervisor2)  Read more

The key to an understanding of the mechanism of many complex reactions came in 1925. In that year Sir Hugh Taylor (1) provided evidence which suggested that atoms and radicals might play important parts as chain carriers in many chemical reactions. Soon after, Rice and his collaborators (2) used Paneth’s (3) metallic mirror test to establish that the thermal decomposition of a number of organic compounds involves these transient species. Using simple elementary reactions involving atoms and free radicals, Rice and Herzfeld were able to devise successful mechanisms for many complex organic decomposition reactions.  Read more

Melatonin is a hormone secreted by the pineal gland, which is known to modulate biological rhythms in mammals. This study investigated the effect of food access schedule and dietary composition on serum melatonin and pineal NAT activity in adult male Wistar rats. These rats were maintained on a 12:12 h light:dark schedule with lights on at 0800h. The rats were randomly assigned to two dietary groups. A group was simultaneously fed a protein-rich and carbohydrate-rich granulated diet and the other group fed granulated rat chow. Each dietary group was further divided based on dietary feeding schedules. Animals were fed between …  Read more

The airspace over the high seas is not a lawless domain. Although the theory of the freedom of the air has been challenged since the beginning of controlled flight, yet 'as regards the air above the high seas, the principle of freedom was never successfully challenged.' [...]  Read more

This study explored the relationship between psychotherapists' personality and choice of theoretical orientation. A total of 493 participants (274 practitioners and 219 students) completed a web-based survey. Personality was assessed using the HEXACO Personality Inventory (HEXACO-PI; Lee & Ashton, 2004) while theoretical orientation preference was assessed using a modified version of the Theoretical Orientation Profile Scale-Revised (TOPS-R; Worthington & Dillon, 2003). In the practitioner sample, the Humanistic/Existential scale was found to be significantly correlated with the Openness Unconventionality scale (r = .34). Results further revealed that practitioners' theoretical orientation preference differed based on the Conscientiousness and Openness personality dimensions. In …  Read more

The prevalence of abnormal pregnancy outcomes in the offspring of 103 epileptic women followed prospectively during pregnancy between 1982 and 1989 was compared with that in the previous study of 119 pregnancies by Dansky et al. from the same institution. Our results have shown a significant decrease in the prevalence of major malformations, as compared with the previous study: 8.8% vs. 24.1% (P $<$ 0.01). Monotherapy was more frequent and the mean number of drugs used during pregnancy was significantly smaller in the present study. Phenytoin, phenobarbital and primidone were prescribed less frequently in the present study, whereas carbamazepine and …  Read more

The landscape of the boreal forest in north-central Canada is characterised by mosaics of broad-leaved deciduous trees (aspen, Populus; birch, Betula), evergreen conifers (black spruce, Picea mariana; jack pine, Pinus banksiana; and larch, Larix), fens and lakes. The forest has been cited as the possible location of a global carbon sink, and its likely response in the event of global climate change remains unclear. To improve our current understanding of the links between the boreal forest ecosystem and the lower atmosphere, the Boreal Ecosystem-Atmosphere Study (BOREAS) was executed in a series of field experiments in 1994 and 1996. This thesis …  Read more

Incubation of adrenals from albino mice (Mus musculus albinus) with adrenocorticotropic hormone (ACTH) or with deoxycorticosterone (DOC) resulted in an increased yield of corticosterone and of lipids with the mobility of 18-hydroxycorticosterone (18-OH-B) and aldosterone. Upon incubation with DOC plus ACTH, additive effects were obtained for corticosterone, but not for the polar lipids, as DOC caused no further increase in these lipids in the presence of ACTH.  Read more

Sugar cane has been the mainstay of the economy of Barbados since 1645 and it has, in spite of the vicissitudes of the sugar industry, maintained this unique position ever since; this can be realised from the fact that it contributes over 90 per cent of the annual income of the island (Macpherson, 1963, p. 75). The predominance of this crop has led to great interest being taken in measures by which a potential yield can be attained. The potential yield, according to Dillewijn (1952, p. xxii), is the maximum yield attainable given that the following five factors are fully …  Read more

Deep-water clastic sediments of the lower Paleozoic continental margin in the Quebec City area are piled up in imbricated thrust sheets and nappes constituting the External Domain of the Northern Appalachians. The youngest sediments (Middle Ordovician Citadelle and Quebec City Formations) occu  Read more

Direct calculation of entrainment and detrainment rates is used to evaluate the Kain-Fritsch convective parameterization scheme in shallow and deep convection. From the large-eddy simulation results, it is found that the Kain-Fritsch estimates of entrainment and detrainment in shallow convection do not accurately reflect the mixing dynamics observed in the high-resolution model. Moreover, the fractional entrainment and detrainment rates are found to be solely dependent on the cloud core buoyancy and vertical velocity, contradicting the assumptions made in the traditional parameterization schemes. A number of parameterizations for fractional entrainment and detrainment rates are presented, as the dynamics that govern the …  Read more

Waters, Kristian (Supervisor2)  Read more

The structure of 8,11,15-trihydroxy-9,12-oxyeicosa-5,13-dienoic acid A, isolated by Pace-Asciak and Wolfe from enzymatic incubation of arachidonic acid, was proven by the synthesis of 8R,9S,11R,12S,15(R and S) isomers 1a and 1b. Both epimers were more polar than the natural product A. Reductive ozonolysis of 1a, followed by reaction of the resulting 2-acetoxyheptanal with l-ephedrine, gave oxazolidines whose R(,f) values on tlc were found to be characteristic of the chirality of the acetoxy group, thus permitting the determination of the absolute stereochemsitry at C-15 of 1a. Model studies towards the synthesis of 9,11,15-trihydroxy-8,12-oxyeicosa-5,13-dienoic acid B were carried out.  Read more

Pinsonneault, Alain (Supervisor1)  Read more

The existing approaches to the detection of precipitation are based on one of the following four techniques: (1) electron microscopy; (2) chemical or electrochemical extraction; (3) the measurement of electrical resistivity; and (4) the analysis of mechanical properties. These techniques can only be used at room temperature on quenched samples. However, the direct measurement of precipitation kinetics at high temperatures is also possible through analysis of the mechanical properties of the specimens. In this work, a creep method was developed and applied to the detection of aluminum nitride precipitation in a dual phase 3% silicon steel. These steels are used …  Read more

We measure the electron density of a single Landau Level of a two-dimensional electron system (2DES) in a GaAs/AlGaAs heterostructure cleaved edge overgrown structure. Edge spectroscopy, which is a powerful technique to probe correlations in 2D systems, has been used. While the 2DEG shows typical fractional quantum Hall features from a many-particle behavior (Luttinger Liquid) at low tunneling voltages, to single particle characteristic at high voltages, which reflects the absence of a many-body state away from the Fermi level. At high enough voltages, the single particle characteristic induces an asymmetry when tunneling into the 2DEG compared to tunneling out of …  Read more

This thesis discusses the background, contents and airpolitical consequences of the so-called 'Horizontal Agreements ("HA"),' concluded by the European Union ("EU") with third countries to give effect to the European Court of Justice's ("Court"/"ECJ") decision of November 2002 in the 'Open Skies' cases brought by the European Commission ("EC"/"Commission") against certain EU Member States. The Court's decision outlaws the nationality or 'ownership and control' clause in the bilateral ('Open Skies') agreements concluded with the United States by those Member States. As this clause is a standard provision in all bilateral air services agreements, the Court's decision actually obliges the Member …  Read more

Bertone, Armando (Supervisor2)  Read more

Studies were made of in vitro cytotoxicity of human serum on rat bone marrow and spleen cells (xenogeneic system) as well as human lymphocytes (allogeneic system). Cytotoxicity was measured by trypan blue staining and C14-uridine incorporation. Human serum donors were classified into two categories: (a) those without previous exposure to human tissue antigens and (b) those possibly presensitized by means of pregnancy, blood transfusion, hemodialysis or renal allograft. All sera from the first group showed natural xenogeneic cytotoxicity but no allogeneic lymphocytotoxicity. Among sera from the second group, some exerted excessive xenogeneic cytotoxicity (heterophile phenomenon) as well as allogeneic lymphocytotoxicity. …  Read more

The phase separation method is a practically important method for producing multicomponent materials. Particularly, many commercialized polymer blends, such as High-Impact Polystyrene (HIPS) and acrylonitrile-butadiene-styrene (ABS), are manufactured by the polymerization-induced phase separation (PIPS) method, polymerizing monomer compounds (styrene) in the presence of polymers (polybutadiene). In this thesis, rigorous mathematical models, describing the PIPS process, have been formulated using the nonlinear Cahn-Hilliard (C-H) theory and the Flory-Huggins (F-H) theory combined with a second-order reaction equation. In particular, this thesis analyzes and simulates for the first time the PIPS process for the case of a monomer polymerizing in the presence of …  Read more

Oxytocin (OT) is a neurohypophyseal hormone that has an important role in mediating uterine contractions during parturition. As preterm labor is a major cause of perinatal mortality, the importance of elucidating the mechanisms involved in parturition become evident. Recently, our lab has discovered a novel mechanism of a non-genomic steroid-induced inhibition of OT receptor (OTR) function (1). It was shown that the steroid hormone progesterone specifically inhibits the rat OTR functions, not the human, via direct binding. Conversely, the human OTR is inhibited by a progesterone metabolite, 5beta-dihydroprogesterone. As there are only a limited number of amino acids that differ …  Read more

In the central nervous system, oligodendrocytes (OLs) form myelin that facilitates conduction of impulses along axons. An individual OL has the unique capability to myelinate up to 50 axons and to produce dramatic quantities of myelin proteins and lipids. The importance of myelin is well reflected in a number of neurological pathologies such as multiple sclerosis, a human demyelinating disease, where severe damage/loss of myelin and OLs are apparent. Although numerous studies have provided evidence of the possibility of remyelination in experimental models, successful remyelination in the demyelinated lesions has not been achieved. One approach to enhance the remyelinating capability …  Read more

This thesis explores Spanish narratives of coexistence in Muslim and Native American lands, collected around the issue of captivity, through a corpus that covers the period of the intellectual history of Spain marked by the struggle against Islam, the Counterreformation and the conquest of America (1492-1609). The first of the works studied is the Viaje de Turquía, a satirical dialogue from the mid-sixteenth century. This text controverts the idea of a rigid separation between Christendom and Islam, West and East, through a comparative critique that argues for a more pluralistic, open and tolerant Spanish society. The second part focuses on …  Read more